Many previous authors treated Cissus incisa and C. trifoliata as distinct species, but the characters used to separate them (size of leaflets, branching patterns of cymes, and berry shape) appear to intergrade abundantly, particularly in Florida, where their geographical ranges overlap. It appears that much of the basis for separating these two species is geographical distribution and habitat, with C. trifoliata being chiefly coastal and tropical and C. incisa being chiefly subtropical and temperate continental. Some authors (for example, R. P. Wunderlin 1982; R. K. Godfrey 1988; J. A. Lombardi 2000) therefore have treated C. incisa as a synonym of C. trifoliata, a conclusion that is followed here.